ABSTRACT
Objective To study the epidemic factors of hemorrhagic fever with renal syndrome (HFRS) in an area in Tianjin in 1997—2005. Methods The descriptive statistical analysis was used to describe the status of HFRS. The Hantavirus(HV) carrier in the mice was investigated and the data of the meteorological, agricultural and population were collected. Rank sum tests were employed to analyze the epidemic of the disease. Results The epidemic of HFRS in the investigated area started from 1997 with annually increasing, the peak was seen in 2002, then it was dropping down. There were 105 cases in total with 4 cases died. The cases were found all over the district, including 11 towns and 70 villages. The cumulative incidence rate was 2.90/100 000, the mortality rate was 0.11/100 000, and the case fatality rate was 3.81%. The seasonal difference was found in this study. The incidences in April and May were highest, accounted for 44.76% of the total cases. The cases in the 30-year-old group accounted for one third of the total occurrence, the ratio of male to female was 3.57∶1. The incidence was highest in the farmers, accounted for 26.67%, in the transient population it accounted for 54.29%. There was a consistency between the index of HV carrier and the epidemic trend. A positive correction was seen between the average temperature and the disease incidence rate (rs=0.746, P=0.021), a negative correction was seen between the precipitation and the incidence rate (rs=-0.695, P=0.038) and between the crop area and the incidence rate (rs=-0.167, P=0.532). Conclusion The investigated area is the epidemic area where HFRS is caused by Seoulvirus(SEOV), the primitive host is Rattusnorvegicus. The main epidemic factors include the transient population massively moved into the area since the mid 1990s, the change of the predominant mice in this area, destruction of the habitats of the mice, the rats migration, the increase of the index of HV and the transformation project of houses and the farmland destruction.
ABSTRACT
Objective To investigate the micronucleus frequency in mice peripheral blood reticulocytes induced by air particulate pollutants in a railway transport station of chemical dangerous goods (RTSCDG) Methods Male BALB/C mice were selected and randomly divided into exposure groups and control groups One time exposure experiment was carried out among mice exposed to acetone extracts of air particulate pollutants at doses of 20,40,80,160 mg/kg by intraperitoneal injection Multiple time exposure experiment was carried out among mice exposed to acetone extacts of air particulate pollutants at dose of 10 mg/kg by consecutive intraperitoneal injection one time per day for 5 days The peripheral blood was sampled from mice tails and the micronucleus frequencies in reticulocytes were observed at 24, 48 and 72 h after the exposure Results The frequencies of micronuclei in peripheral blood reticulocytes revealed good time response relationship and reached the highest levels at 48 h after exposure,at the same time the frequencies of micronuclei in dose groups of 20,40,80,160 mg/kg were all higher than those in control group The multiple frequencies exposure experiment with lower dose showed that the frequencies of micronuclei in peripheral blood reticulocytes in exposure group always revealed significantly higher levels compared with those in control group during the 24th~72th hour after the exposure ( P
ABSTRACT
Objective To know the effect ofof the particulates sampled from the air of the railway transport station of hazard chemicals on rat typeⅡpneumocytes and the antagonism of antioxidants. Methods The rat typeⅡpneumocytes cultured by routine method were pre-treated with antioxidants N-acetylcysteine (NAC), Vitamin C and Vitamin E, then were exposed to the abstract of particulates. The damages of rat typeⅡpneumocytes and DNA cross-links were detected with MTT assay and ethidium bromide fluorescence assay. Results The abstract of particulates caused obvious damages and DNA cross-links in the rat typeⅡpneumocytes and the significant dose-effect relationship was seen. NAC, Vitamin C and Vitamin E reduced significantly the damages and DNA cross-links. Conclusion Abstract of the particulates sampled from the air of the railway transport station of hazard chemicals may induce the damages and DNA cross-links in rat typeⅡpneumocytes and these adverse effects can be antagonized by antioxidants such as NAC, Vitamin C and Vitamin E.